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Diffstat (limited to 'arch/x86/kernel/entry_32.S')
-rw-r--r--arch/x86/kernel/entry_32.S451
1 files changed, 288 insertions, 163 deletions
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 46469029e9d..e9920683145 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -30,12 +30,13 @@
* 1C(%esp) - %ds
* 20(%esp) - %es
* 24(%esp) - %fs
- * 28(%esp) - orig_eax
- * 2C(%esp) - %eip
- * 30(%esp) - %cs
- * 34(%esp) - %eflags
- * 38(%esp) - %oldesp
- * 3C(%esp) - %oldss
+ * 28(%esp) - %gs saved iff !CONFIG_X86_32_LAZY_GS
+ * 2C(%esp) - orig_eax
+ * 30(%esp) - %eip
+ * 34(%esp) - %cs
+ * 38(%esp) - %eflags
+ * 3C(%esp) - %oldesp
+ * 40(%esp) - %oldss
*
* "current" is in register %ebx during any slow entries.
*/
@@ -101,121 +102,221 @@
#define resume_userspace_sig resume_userspace
#endif
-#define SAVE_ALL \
- cld; \
- pushl %fs; \
- CFI_ADJUST_CFA_OFFSET 4;\
- /*CFI_REL_OFFSET fs, 0;*/\
- pushl %es; \
- CFI_ADJUST_CFA_OFFSET 4;\
- /*CFI_REL_OFFSET es, 0;*/\
- pushl %ds; \
- CFI_ADJUST_CFA_OFFSET 4;\
- /*CFI_REL_OFFSET ds, 0;*/\
- pushl %eax; \
- CFI_ADJUST_CFA_OFFSET 4;\
- CFI_REL_OFFSET eax, 0;\
- pushl %ebp; \
- CFI_ADJUST_CFA_OFFSET 4;\
- CFI_REL_OFFSET ebp, 0;\
- pushl %edi; \
- CFI_ADJUST_CFA_OFFSET 4;\
- CFI_REL_OFFSET edi, 0;\
- pushl %esi; \
- CFI_ADJUST_CFA_OFFSET 4;\
- CFI_REL_OFFSET esi, 0;\
- pushl %edx; \
- CFI_ADJUST_CFA_OFFSET 4;\
- CFI_REL_OFFSET edx, 0;\
- pushl %ecx; \
- CFI_ADJUST_CFA_OFFSET 4;\
- CFI_REL_OFFSET ecx, 0;\
- pushl %ebx; \
- CFI_ADJUST_CFA_OFFSET 4;\
- CFI_REL_OFFSET ebx, 0;\
- movl $(__USER_DS), %edx; \
- movl %edx, %ds; \
- movl %edx, %es; \
- movl $(__KERNEL_PERCPU), %edx; \
+/*
+ * User gs save/restore
+ *
+ * %gs is used for userland TLS and kernel only uses it for stack
+ * canary which is required to be at %gs:20 by gcc. Read the comment
+ * at the top of stackprotector.h for more info.
+ *
+ * Local labels 98 and 99 are used.
+ */
+#ifdef CONFIG_X86_32_LAZY_GS
+
+ /* unfortunately push/pop can't be no-op */
+.macro PUSH_GS
+ pushl $0
+ CFI_ADJUST_CFA_OFFSET 4
+.endm
+.macro POP_GS pop=0
+ addl $(4 + \pop), %esp
+ CFI_ADJUST_CFA_OFFSET -(4 + \pop)
+.endm
+.macro POP_GS_EX
+.endm
+
+ /* all the rest are no-op */
+.macro PTGS_TO_GS
+.endm
+.macro PTGS_TO_GS_EX
+.endm
+.macro GS_TO_REG reg
+.endm
+.macro REG_TO_PTGS reg
+.endm
+.macro SET_KERNEL_GS reg
+.endm
+
+#else /* CONFIG_X86_32_LAZY_GS */
+
+.macro PUSH_GS
+ pushl %gs
+ CFI_ADJUST_CFA_OFFSET 4
+ /*CFI_REL_OFFSET gs, 0*/
+.endm
+
+.macro POP_GS pop=0
+98: popl %gs
+ CFI_ADJUST_CFA_OFFSET -4
+ /*CFI_RESTORE gs*/
+ .if \pop <> 0
+ add $\pop, %esp
+ CFI_ADJUST_CFA_OFFSET -\pop
+ .endif
+.endm
+.macro POP_GS_EX
+.pushsection .fixup, "ax"
+99: movl $0, (%esp)
+ jmp 98b
+.section __ex_table, "a"
+ .align 4
+ .long 98b, 99b
+.popsection
+.endm
+
+.macro PTGS_TO_GS
+98: mov PT_GS(%esp), %gs
+.endm
+.macro PTGS_TO_GS_EX
+.pushsection .fixup, "ax"
+99: movl $0, PT_GS(%esp)
+ jmp 98b
+.section __ex_table, "a"
+ .align 4
+ .long 98b, 99b
+.popsection
+.endm
+
+.macro GS_TO_REG reg
+ movl %gs, \reg
+ /*CFI_REGISTER gs, \reg*/
+.endm
+.macro REG_TO_PTGS reg
+ movl \reg, PT_GS(%esp)
+ /*CFI_REL_OFFSET gs, PT_GS*/
+.endm
+.macro SET_KERNEL_GS reg
+ movl $(__KERNEL_STACK_CANARY), \reg
+ movl \reg, %gs
+.endm
+
+#endif /* CONFIG_X86_32_LAZY_GS */
+
+.macro SAVE_ALL
+ cld
+ PUSH_GS
+ pushl %fs
+ CFI_ADJUST_CFA_OFFSET 4
+ /*CFI_REL_OFFSET fs, 0;*/
+ pushl %es
+ CFI_ADJUST_CFA_OFFSET 4
+ /*CFI_REL_OFFSET es, 0;*/
+ pushl %ds
+ CFI_ADJUST_CFA_OFFSET 4
+ /*CFI_REL_OFFSET ds, 0;*/
+ pushl %eax
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET eax, 0
+ pushl %ebp
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET ebp, 0
+ pushl %edi
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET edi, 0
+ pushl %esi
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET esi, 0
+ pushl %edx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET edx, 0
+ pushl %ecx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET ecx, 0
+ pushl %ebx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET ebx, 0
+ movl $(__USER_DS), %edx
+ movl %edx, %ds
+ movl %edx, %es
+ movl $(__KERNEL_PERCPU), %edx
movl %edx, %fs
+ SET_KERNEL_GS %edx
+.endm
-#define RESTORE_INT_REGS \
- popl %ebx; \
- CFI_ADJUST_CFA_OFFSET -4;\
- CFI_RESTORE ebx;\
- popl %ecx; \
- CFI_ADJUST_CFA_OFFSET -4;\
- CFI_RESTORE ecx;\
- popl %edx; \
- CFI_ADJUST_CFA_OFFSET -4;\
- CFI_RESTORE edx;\
- popl %esi; \
- CFI_ADJUST_CFA_OFFSET -4;\
- CFI_RESTORE esi;\
- popl %edi; \
- CFI_ADJUST_CFA_OFFSET -4;\
- CFI_RESTORE edi;\
- popl %ebp; \
- CFI_ADJUST_CFA_OFFSET -4;\
- CFI_RESTORE ebp;\
- popl %eax; \
- CFI_ADJUST_CFA_OFFSET -4;\
+.macro RESTORE_INT_REGS
+ popl %ebx
+ CFI_ADJUST_CFA_OFFSET -4
+ CFI_RESTORE ebx
+ popl %ecx
+ CFI_ADJUST_CFA_OFFSET -4
+ CFI_RESTORE ecx
+ popl %edx
+ CFI_ADJUST_CFA_OFFSET -4
+ CFI_RESTORE edx
+ popl %esi
+ CFI_ADJUST_CFA_OFFSET -4
+ CFI_RESTORE esi
+ popl %edi
+ CFI_ADJUST_CFA_OFFSET -4
+ CFI_RESTORE edi
+ popl %ebp
+ CFI_ADJUST_CFA_OFFSET -4
+ CFI_RESTORE ebp
+ popl %eax
+ CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE eax
+.endm
-#define RESTORE_REGS \
- RESTORE_INT_REGS; \
-1: popl %ds; \
- CFI_ADJUST_CFA_OFFSET -4;\
- /*CFI_RESTORE ds;*/\
-2: popl %es; \
- CFI_ADJUST_CFA_OFFSET -4;\
- /*CFI_RESTORE es;*/\
-3: popl %fs; \
- CFI_ADJUST_CFA_OFFSET -4;\
- /*CFI_RESTORE fs;*/\
-.pushsection .fixup,"ax"; \
-4: movl $0,(%esp); \
- jmp 1b; \
-5: movl $0,(%esp); \
- jmp 2b; \
-6: movl $0,(%esp); \
- jmp 3b; \
-.section __ex_table,"a";\
- .align 4; \
- .long 1b,4b; \
- .long 2b,5b; \
- .long 3b,6b; \
+.macro RESTORE_REGS pop=0
+ RESTORE_INT_REGS
+1: popl %ds
+ CFI_ADJUST_CFA_OFFSET -4
+ /*CFI_RESTORE ds;*/
+2: popl %es
+ CFI_ADJUST_CFA_OFFSET -4
+ /*CFI_RESTORE es;*/
+3: popl %fs
+ CFI_ADJUST_CFA_OFFSET -4
+ /*CFI_RESTORE fs;*/
+ POP_GS \pop
+.pushsection .fixup, "ax"
+4: movl $0, (%esp)
+ jmp 1b
+5: movl $0, (%esp)
+ jmp 2b
+6: movl $0, (%esp)
+ jmp 3b
+.section __ex_table, "a"
+ .align 4
+ .long 1b, 4b
+ .long 2b, 5b
+ .long 3b, 6b
.popsection
+ POP_GS_EX
+.endm
-#define RING0_INT_FRAME \
- CFI_STARTPROC simple;\
- CFI_SIGNAL_FRAME;\
- CFI_DEF_CFA esp, 3*4;\
- /*CFI_OFFSET cs, -2*4;*/\
+.macro RING0_INT_FRAME
+ CFI_STARTPROC simple
+ CFI_SIGNAL_FRAME
+ CFI_DEF_CFA esp, 3*4
+ /*CFI_OFFSET cs, -2*4;*/
CFI_OFFSET eip, -3*4
+.endm
-#define RING0_EC_FRAME \
- CFI_STARTPROC simple;\
- CFI_SIGNAL_FRAME;\
- CFI_DEF_CFA esp, 4*4;\
- /*CFI_OFFSET cs, -2*4;*/\
+.macro RING0_EC_FRAME
+ CFI_STARTPROC simple
+ CFI_SIGNAL_FRAME
+ CFI_DEF_CFA esp, 4*4
+ /*CFI_OFFSET cs, -2*4;*/
CFI_OFFSET eip, -3*4
+.endm
-#define RING0_PTREGS_FRAME \
- CFI_STARTPROC simple;\
- CFI_SIGNAL_FRAME;\
- CFI_DEF_CFA esp, PT_OLDESP-PT_EBX;\
- /*CFI_OFFSET cs, PT_CS-PT_OLDESP;*/\
- CFI_OFFSET eip, PT_EIP-PT_OLDESP;\
- /*CFI_OFFSET es, PT_ES-PT_OLDESP;*/\
- /*CFI_OFFSET ds, PT_DS-PT_OLDESP;*/\
- CFI_OFFSET eax, PT_EAX-PT_OLDESP;\
- CFI_OFFSET ebp, PT_EBP-PT_OLDESP;\
- CFI_OFFSET edi, PT_EDI-PT_OLDESP;\
- CFI_OFFSET esi, PT_ESI-PT_OLDESP;\
- CFI_OFFSET edx, PT_EDX-PT_OLDESP;\
- CFI_OFFSET ecx, PT_ECX-PT_OLDESP;\
+.macro RING0_PTREGS_FRAME
+ CFI_STARTPROC simple
+ CFI_SIGNAL_FRAME
+ CFI_DEF_CFA esp, PT_OLDESP-PT_EBX
+ /*CFI_OFFSET cs, PT_CS-PT_OLDESP;*/
+ CFI_OFFSET eip, PT_EIP-PT_OLDESP
+ /*CFI_OFFSET es, PT_ES-PT_OLDESP;*/
+ /*CFI_OFFSET ds, PT_DS-PT_OLDESP;*/
+ CFI_OFFSET eax, PT_EAX-PT_OLDESP
+ CFI_OFFSET ebp, PT_EBP-PT_OLDESP
+ CFI_OFFSET edi, PT_EDI-PT_OLDESP
+ CFI_OFFSET esi, PT_ESI-PT_OLDESP
+ CFI_OFFSET edx, PT_EDX-PT_OLDESP
+ CFI_OFFSET ecx, PT_ECX-PT_OLDESP
CFI_OFFSET ebx, PT_EBX-PT_OLDESP
+.endm
ENTRY(ret_from_fork)
CFI_STARTPROC
@@ -362,6 +463,7 @@ sysenter_exit:
xorl %ebp,%ebp
TRACE_IRQS_ON
1: mov PT_FS(%esp), %fs
+ PTGS_TO_GS
ENABLE_INTERRUPTS_SYSEXIT
#ifdef CONFIG_AUDITSYSCALL
@@ -410,6 +512,7 @@ sysexit_audit:
.align 4
.long 1b,2b
.popsection
+ PTGS_TO_GS_EX
ENDPROC(ia32_sysenter_target)
# system call handler stub
@@ -452,8 +555,7 @@ restore_all:
restore_nocheck:
TRACE_IRQS_IRET
restore_nocheck_notrace:
- RESTORE_REGS
- addl $4, %esp # skip orig_eax/error_code
+ RESTORE_REGS 4 # skip orig_eax/error_code
CFI_ADJUST_CFA_OFFSET -4
irq_return:
INTERRUPT_RETURN
@@ -595,28 +697,50 @@ syscall_badsys:
END(syscall_badsys)
CFI_ENDPROC
-#define FIXUP_ESPFIX_STACK \
- /* since we are on a wrong stack, we cant make it a C code :( */ \
- PER_CPU(gdt_page, %ebx); \
- GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah); \
- addl %esp, %eax; \
- pushl $__KERNEL_DS; \
- CFI_ADJUST_CFA_OFFSET 4; \
- pushl %eax; \
- CFI_ADJUST_CFA_OFFSET 4; \
- lss (%esp), %esp; \
- CFI_ADJUST_CFA_OFFSET -8;
-#define UNWIND_ESPFIX_STACK \
- movl %ss, %eax; \
- /* see if on espfix stack */ \
- cmpw $__ESPFIX_SS, %ax; \
- jne 27f; \
- movl $__KERNEL_DS, %eax; \
- movl %eax, %ds; \
- movl %eax, %es; \
- /* switch to normal stack */ \
- FIXUP_ESPFIX_STACK; \
-27:;
+/*
+ * System calls that need a pt_regs pointer.
+ */
+#define PTREGSCALL(name) \
+ ALIGN; \
+ptregs_##name: \
+ leal 4(%esp),%eax; \
+ jmp sys_##name;
+
+PTREGSCALL(iopl)
+PTREGSCALL(fork)
+PTREGSCALL(clone)
+PTREGSCALL(vfork)
+PTREGSCALL(execve)
+PTREGSCALL(sigaltstack)
+PTREGSCALL(sigreturn)
+PTREGSCALL(rt_sigreturn)
+PTREGSCALL(vm86)
+PTREGSCALL(vm86old)
+
+.macro FIXUP_ESPFIX_STACK
+ /* since we are on a wrong stack, we cant make it a C code :( */
+ PER_CPU(gdt_page, %ebx)
+ GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah)
+ addl %esp, %eax
+ pushl $__KERNEL_DS
+ CFI_ADJUST_CFA_OFFSET 4
+ pushl %eax
+ CFI_ADJUST_CFA_OFFSET 4
+ lss (%esp), %esp
+ CFI_ADJUST_CFA_OFFSET -8
+.endm
+.macro UNWIND_ESPFIX_STACK
+ movl %ss, %eax
+ /* see if on espfix stack */
+ cmpw $__ESPFIX_SS, %ax
+ jne 27f
+ movl $__KERNEL_DS, %eax
+ movl %eax, %ds
+ movl %eax, %es
+ /* switch to normal stack */
+ FIXUP_ESPFIX_STACK
+27:
+.endm
/*
* Build the entry stubs and pointer table with some assembler magic.
@@ -672,7 +796,7 @@ common_interrupt:
ENDPROC(common_interrupt)
CFI_ENDPROC
-#define BUILD_INTERRUPT(name, nr) \
+#define BUILD_INTERRUPT3(name, nr, fn) \
ENTRY(name) \
RING0_INT_FRAME; \
pushl $~(nr); \
@@ -680,13 +804,15 @@ ENTRY(name) \
SAVE_ALL; \
TRACE_IRQS_OFF \
movl %esp,%eax; \
- call smp_##name; \
+ call fn; \
jmp ret_from_intr; \
CFI_ENDPROC; \
ENDPROC(name)
+#define BUILD_INTERRUPT(name, nr) BUILD_INTERRUPT3(name, nr, smp_##name)
+
/* The include is where all of the SMP etc. interrupts come from */
-#include "entry_arch.h"
+#include <asm/entry_arch.h>
ENTRY(coprocessor_error)
RING0_INT_FRAME
@@ -1068,7 +1194,10 @@ ENTRY(page_fault)
CFI_ADJUST_CFA_OFFSET 4
ALIGN
error_code:
- /* the function address is in %fs's slot on the stack */
+ /* the function address is in %gs's slot on the stack */
+ pushl %fs
+ CFI_ADJUST_CFA_OFFSET 4
+ /*CFI_REL_OFFSET fs, 0*/
pushl %es
CFI_ADJUST_CFA_OFFSET 4
/*CFI_REL_OFFSET es, 0*/
@@ -1097,20 +1226,15 @@ error_code:
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET ebx, 0
cld
- pushl %fs
- CFI_ADJUST_CFA_OFFSET 4
- /*CFI_REL_OFFSET fs, 0*/
movl $(__KERNEL_PERCPU), %ecx
movl %ecx, %fs
UNWIND_ESPFIX_STACK
- popl %ecx
- CFI_ADJUST_CFA_OFFSET -4
- /*CFI_REGISTER es, ecx*/
- movl PT_FS(%esp), %edi # get the function address
+ GS_TO_REG %ecx
+ movl PT_GS(%esp), %edi # get the function address
movl PT_ORIG_EAX(%esp), %edx # get the error code
movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart
- mov %ecx, PT_FS(%esp)
- /*CFI_REL_OFFSET fs, ES*/
+ REG_TO_PTGS %ecx
+ SET_KERNEL_GS %ecx
movl $(__USER_DS), %ecx
movl %ecx, %ds
movl %ecx, %es
@@ -1134,26 +1258,27 @@ END(page_fault)
* by hand onto the new stack - while updating the return eip past
* the instruction that would have done it for sysenter.
*/
-#define FIX_STACK(offset, ok, label) \
- cmpw $__KERNEL_CS,4(%esp); \
- jne ok; \
-label: \
- movl TSS_sysenter_sp0+offset(%esp),%esp; \
- CFI_DEF_CFA esp, 0; \
- CFI_UNDEFINED eip; \
- pushfl; \
- CFI_ADJUST_CFA_OFFSET 4; \
- pushl $__KERNEL_CS; \
- CFI_ADJUST_CFA_OFFSET 4; \
- pushl $sysenter_past_esp; \
- CFI_ADJUST_CFA_OFFSET 4; \
+.macro FIX_STACK offset ok label
+ cmpw $__KERNEL_CS, 4(%esp)
+ jne \ok
+\label:
+ movl TSS_sysenter_sp0 + \offset(%esp), %esp
+ CFI_DEF_CFA esp, 0
+ CFI_UNDEFINED eip
+ pushfl
+ CFI_ADJUST_CFA_OFFSET 4
+ pushl $__KERNEL_CS
+ CFI_ADJUST_CFA_OFFSET 4
+ pushl $sysenter_past_esp
+ CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET eip, 0
+.endm
ENTRY(debug)
RING0_INT_FRAME
cmpl $ia32_sysenter_target,(%esp)
jne debug_stack_correct
- FIX_STACK(12, debug_stack_correct, debug_esp_fix_insn)
+ FIX_STACK 12, debug_stack_correct, debug_esp_fix_insn
debug_stack_correct:
pushl $-1 # mark this as an int
CFI_ADJUST_CFA_OFFSET 4
@@ -1211,7 +1336,7 @@ nmi_stack_correct:
nmi_stack_fixup:
RING0_INT_FRAME
- FIX_STACK(12,nmi_stack_correct, 1)
+ FIX_STACK 12, nmi_stack_correct, 1
jmp nmi_stack_correct
nmi_debug_stack_check:
@@ -1222,7 +1347,7 @@ nmi_debug_stack_check:
jb nmi_stack_correct
cmpl $debug_esp_fix_insn,(%esp)
ja nmi_stack_correct
- FIX_STACK(24,nmi_stack_correct, 1)
+ FIX_STACK 24, nmi_stack_correct, 1
jmp nmi_stack_correct
nmi_espfix_stack: